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The emerging Internet of Things paradigm has triggered an explosion in ad-hoc applications that require connectivity among the nodes of wireless networks. However, the channel randomness and the random deployment of such networks could cause missed detections by isolated (i.e., unable to disseminate their messages) or inactive (i.e., without enough energy to transmit) nodes. Moreover, as the number of nodes increases, the use of "green" solutions such as wireless energy harvesting for powering battery-less devices could eliminate the maintenance costs and boost immensely the network lifetime. In this paper, we study the connectivity in a wireless-powered sensor network (WPSN) with battery-less devices under two common routing schemes, namely unicast and broadcast. We provide an analytical model for the ability of a WPSN to be reliable and evaluate the trade-offs among the different scenarios via simulation. ; Grant numbers : This work has been funded by the Catalan Government (2014-SGR-1551) and CellFive (TEC2014-60130-P).© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Facing the increasing energy demands associated with the perspective of fifth generation (5G) wireless networks, the Mobile Network Operators (MNOs) are motivated to gradually convert their traditional Radio Access Network (RAN) infrastructure to more flexible and power efficient centralized architectures, i.e., Cloud-RAN (C-RAN). Apart from their promising benefits in terms of management and network optimization, these new architectures further enable the sharing of spectrum and network elements, such as the Remote Radio Heads (RRHs) and the Baseband Units (BBUs), among multiple operators. In this paper, we introduce a novel scheme based on coalitional game theory to identify the potential room for cooperation among different MNOs that provide service to the same area. The proposed scheme sets the rules for profitable collaboration and identifies the core formation conditions (i.e., pricing) for various scenarios with different market and spectrum shares among three operators. Our results show that i) cooperation among subcoalitions of MNOs is always beneficial, yielding both higher revenues and enhanced Quality of Service (QoS) for the end users, and ii) the cooperation of all operators (grand coalition) is profitable for given user pricing in different scenarios. ; Grant numbers : This work has been funded by the research projects the Catalan Government (2014-SGR-1551) and CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. (2014 SGR 1551), CellFive (TEC2014-60130-P).

Small cells (SCs) are expected to be densely deployed during the next few years to enhance the network capacity of future heterogeneous networks (HetNets). Due to their dense deployment, not all SCs are expected to have a direct connection to the core network. As a result, some SCs will forward their traffic to the neighboring SCs until they reach the core network, thus forming a multi-hop backhaul (BH) network. Due to the large number of BH links, the BH is expected to be one of the main challenges that future HetNets will have to face. At the same time, traffic demands are growing exponentially resulting in higher energy consumption. Therefore, how to achieve high network energy efficiency becomes of utmost importance. To that end, in this paper, we study the role of BH in future outdoor HetNets aiming to answer to whether or not it could constitute an energy bottleneck for the HetNet. To gain insights, we study the BH energy consumption impact compared to the access network under different traffic distribution scenarios and BH technologies. ; Grant number : This work has been funded by the Catalan Government 2014-SGR-1551.© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

As wearables provide new health-related functionalities, they can be employed in hospitals to monitor patients and notify the medical personnel regarding their status. However, in order to be approved by the medical community, wearables need to have reliable communication and high lifetime. In such scenarios, it is important to know the probability of correct notification which is affected mainly by the deployment of the wireless wearables and their energy supply. Typically, rooms in hospitals host multiple people and, thus, a clustered communication model should be adopted for more trustworthy results. Moreover, by employing wireless charging, it is possible to provide an uninterrupted operation with high reliability. Therefore, in this paper, we study the aforementioned probability in a clustered network while the wearable devices are wirelessly charged. We provide an analytical model for the wearables' ability to inform quickly the medical personnel and discuss different trade-offs via extensive simulations. ; Grant numbers : This work has been funded by the Catalan Government (2014-SGR-1551) and the research projects CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The economical recession of the recent years has affected the economies of European countries and the welfare of their population and markets. In this paper, we focus on the northern and southern European population "at-risk-of-poverty" and study the impact of economical instability of the 2008–2015 period on their behaviour as consumers towards the offered Internet services basket. Intrigued by the contrasting profile of economies of the northern and southern countries, we have selected three representatives of each party (Germany, the Netherlands and Finland for North Europe and Spain, Portugal and Greece for South Europe) to provide a comparison analysis of the Internet services market for the poor during the economical crisis years. In order to obtain further insights, we also proceed to a comparison with the average consumer behaviour of poor population in Europe. Our findings suggest that Internet services can be either a basic need or luxury and that their demand is on the rise despite possible income reduction during crisis. ; Grant numbers : This work has been funded by the Research Projects of the Catalan Government (2014 SGR 1551), CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

As large-scale dense and often randomly deployed wireless sensor networks (WSNs) become widespread, local information exchange between colocated sets of nodes may play a significant role in handling the excessive traffic volume. Moreover, to account for the limited life-span of the wireless devices, harvesting the energy of the network transmissions provides significant benefits to the lifetime of such networks. In this paper, we study the performance of communication in dense networks with wireless energy harvesting (WEH)-enabled sensor nodes. In particular, we examine two different communication scenarios (direct and cooperative) for data exchange and we provide theoretical expressions for the probability of successful communication. Then, considering the importance of lifetime in WSNs, we employ state-of-the-art WEH techniques and realistic energy converters, quantifying the potential energy gains that can be achieved in the network. Our analytical derivations, which are validated by extensive Monte-Carlo simulations, highlight the importance of WEH in dense networks and identify the tradeoffs between the direct and cooperative communication scenarios. ; Grant numbers : This work was supported by the projects Cellfive (TEC2014-60130-P) and AGAUR the Catalan Government (2014-SGR-1551).© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.